U.S. Special Forces attempted to free James Foley, the American journalist beheaded by the Islamic State (ISIS), earlier this summer, but Foley and other American hostages thought to have been at the location inside Syria were not there.

Pentagon spokesman Rear Adm. John Kirby revealed Wednesday night that several dozen Special Forces members landed inside Syria at a location where intelligence had indicated the Americans were being held.

But The New York Times reported that some Defense officials were outraged that the mission had been revealed. One told the Times that the militants now knew the Americans’ desire and willingness to try to rescue the hostages. That would likely make any new missions very difficult.

The new details include things that ISIS is not likely to have known.

“This only makes our job harder,” the official told the Times. “I’m very disappointed this was released. We knew any second operation would be a lot harder.”

Caitlin Hayden, the National Security Council spokeswoman, said in a statement to the Times that the administration had “never intended to disclose this operation” but had felt that its hand was forced by news media outlets that were preparing to report on the mission.

“An overriding concern for the safety of the hostages and for operational security made it imperative that we preserve as much secrecy as possible," Hayden said.

The elite group came in by helicopter, backed up by combat, surveillance, and intelligence aircraft, CNN reported Wednesday night.

When they got to the facility, they engaged ISIS fighters on the ground and killed several of them. Though one of the Special Forces members was wounded, none was killed.

CNN's Barbara Starr said the forces were going after a particular segment of the Islamic State that they thought was holding Foley and others at the undisclosed location.

The Pentagon would not say how its intelligence was obtained, but Starr noted that some hostages who have come out of Syria have reported some details of their captivity.

"That is about as dangerous as it gets," Starr said of the operation, noting that had the Special Forces troops been discovered, they risked attack by the Bashar Assad regime or by ISIS itself.

A White House statement said President Barack Obama authorized the action because the national security team thought the hostages were in increasing danger.

"The U.S. government had what we believed was sufficient intelligence, and when the opportunity presented itself, the president authorized the Department of Defense to move aggressively to recover our citizens," said Lisa Monaco, Obama's top counter-terrorism adviser. "Unfortunately, that mission was ultimately not successful because the hostages were not present."

Officials disclosed the rescue operation a day after the militants released a video showing the beheading of Foley and threatened to kill a second hostage, Steven Sotloff, if U.S. airstrikes against the militants in Iraq continued.

Despite the militants' threats, the U.S. launched a new barrage of airstrikes against Islamic State targets in Syria on Wednesday. The Obama administration did not rule out the prospect of a military operation in Syria to bring those responsible for Foley's death to justice.

The disclosure of the rescue mission marks the first time the United States has revealed that U.S. military personnel had been on the ground in Syria since a bloody civil war there broke out more than three years ago.

Obama has resisted calls to insert the U.S. military into the middle of Syria's civil war, a cautious approach that his critics say has allowed the Islamic State to strengthen there and make gains across the border in Iraq.

"As we have said repeatedly, the United States government is committed to the safety and well-being of its citizens, particularly those suffering in captivity. In this case, we put the best of the United States military in harm's way to try and bring our citizens home," Pentagon spokesman Kirby said.

"The United States government uses the full breadth of our military, intelligence, and diplomatic capabilities to bring people home whenever we can. The United States will not tolerate the abduction of our people, and will work tirelessly to secure the safety of our citizens and to hold their captors accountable."

It's unclear how many Americans the special forces attempted to rescue in Syria. While the officials who described the mission would not provide an exact number, other U.S. officials, who were not authorized to speak publicly, have said Foley was one of at least four Americans held in Syria.

Like Foley, two others are thought to have been kidnapped by the Islamic State. The fourth, freelance journalist Austin Tice, disappeared in Syria in August 2012 and is thought to be in the custody of government forces there.

Administration officials would not say specifically when or where the operation took place, citing the need to protect operational details in order to preserve the ability to carry out future rescue missions. They did say that nearly every branch of the military was involved and that the Special Forces on the ground were supported from the air by fixed wing, rotary, and surveillance aircraft.

Obama has authorized previous military missions to rescue hostages. In 2009, Navy SEAL snipers carried out a daring sea operation to rescue an American ship captain held by Somali pirates in a lifeboat. In 2012, Special Forces successfully rescued an American and Dutch aid worked held in Somalia.

Gen. Michael Hayden, former director of the Central Intelligence Agency and the National Security Agency, told Newsmax that it is impossible to dissuade or deter ISIS from brutally executing hostages.

"We really did get a chance yesterday to look at absolute evil in its face. It's a reminder of what it is we're dealing with here in the Middle East," said Hayden, a retired Air Force general.

ISIS members uploaded a video of the beheading on the Internet, saying it was retaliation for U.S. military action against them. ISIS has threatened to kill more American hostages.

Does anyone else get the impression that we have Muslim Brotherhood Operatives stationed throughout all branches of our government now? That this White House seems to do everything it can to aid and abet the enemy?